Thursday, January 28, 2016

The Truth About Grit

"Provide quality grit and there is no need to worm your chickens."  - Statement made by a fan on the Chicken Whisperer Facebook page posted on January 14, 2016.

Grit is not a poultry de-wormer.  Grit consists of small stones that are consumed by chickens to help with the grinding up of whole grains in the gizzard.  The gizzard is a very strong muscle with a tough inner lining.  The grit simply adds surface area to the grinding that takes place in the gizzard to make this process more efficient.  With most poultry feeds today, there are no whole grains and so grit is not necessary.  If you do not feed whole grains, then not purchasing grit is a cost savings to the chicken owner.  Chickens, if allowed to range in the yard or the driveway, often pick up small stones and consume them.  You will also see smaller bird species doing the same thing (i.e. sparrows).  Grit eventually wears down to the point that it is small enough to leave the gizzard.  It then passes out in the feces.  Grit is not the same as oyster shell.  Oyster shell imparts additional calcium to the bird’s diet and can strengthen eggshells during times of stress when birds may be laying weaker eggshells. 

At some point, someone suggested that grit scrapes the worms or damages the worms to the point of causing them to be released from the body.  There is no evidence that grit is effective in this way for poultry.  Some backyard chicken owners thought that grit was similar to food grade diatomaceous earth (DE), which is only slightly effective against worms.  Since both DE and grit are both come from the ground, at some point some people equated the two as having similar uses.  It should also be noted that on the internet, pumpkin seed research on small ruminants, is being purported as a good, natural de-wormer for chickens.  There has been no research done on the effectiveness of pumpkin seeds as a de-wormer in chickens. 

There is only one over-the-counter chicken de-wormer on the market and the active ingredient is piperazine.  The brand names vary, but the active ingredient is the same.  It is added to the water, not the feed.  There are no approved over-the-counter poultry de-wormers approved for the feed in the U.S.  Piperazine will not kill worms.  It simply makes them sleepy and hopefully they will let go of the lining of the intestines.  If, and when, they let go, they are pushed out of the body through normal peristaltic action. That is why it is suggested that birds receive a good dose of the medication followed a few hours later by a thorough cleaning of the coop bedding because the feces are likely worm-laden. The birds receive a good dose by taking their normal water away for a few hours (depending of course on the time of year in case temperatures are excessively high) and then put the medicated water into the coop.  Keep the medicated water in the coop for a few hours and then take it out.  Wash the waterer out with soap and water and then refill the waterer with fresh, clean, cool water.  Worms can still move in the feces and it is important that the feces are cleaned up as the chickens are likely to be attracted to the movement in the droppings.  Re-infection via the fecal-oral route is a common tactic used by internal parasites to ensure that they survive and pass along their genes to the next generation. 

That does not mean that there are no other products out there.  Some are herbal with no scientific proof of the product’s effectiveness in different types of poultry under different housing conditions.  Be wary of claims that point toward non-poultry research or claims that they are traditionally accepted as de-wormers.  If the research has not been done with regard to 1) effectiveness against different types of poultry internal parasites, and 2) withdrawal periods for meat and eggs, then you are making a very large assumption that the product will work in your situation.  

There are products out there that are acceptable to give to poultry with a veterinarian’s prescription and oversight.  Prevention is the key as most backyard flock owners do not want to give their chickens too many drugs.  Many small flock owners get a small flock because they believe that commercial production practices already use too many chemicals. Commercial producers cannot afford to give their chickens medications unnecessarily and so use biosecurity to their advantage as a preventative measure.  They also do not expose their birds to sources of internal parasites.  Some small flock owners expose their birds to wild birds and insects which can either be intermediate hosts of internal parasites or cause infection directly.  Therefore many small flock owners just want to be able to give drugs to their flock monthly to prevent worms.  This may lead to a build-up of resistant worms, potentially reducing the effectiveness of the only over-the-counter product currently available in the U.S.  To avoid giving your small flock drugs unnecessarily, it is recommended that a sample of fresh feces be taken to your veterinarian to have fecal flotation test be done.  This test determines if worm eggs are in the feces and a microscope is needed for this examination.  Only if your chickens have evidence of worms should you consider treating them with piperazine.  The sheep and goat producers worldwide are currently experiencing difficulties with a lack of available drugs and internal parasites that are resistant to the drugs that remain available.  No one wants a similar situation to occur for small flock owners. 

Response provided by Dr. Brigid McCrea, Ph.D.
Associate Professor and Extension Poultry Specialist

Delaware State University